Identification of distant metastases with PET-CT in patients with suspected recurrent head and neck cancer

Objectives: To investigate the utility of positron-emission tomography/computed tomography (PET-CT) in identifying distant metastatic disease in patients with suspected recurrent head and neck squamous cell cancer (HNSCC). Study Design: Retrospective analysis. Methods: Retrospective analysis of 64 consecutive patients with suspected recurrent HNSCC following definitive treatment who underwent PET-CT imaging were eligible for inclusion. Patients with previous known distant metastatic disease were excluded. Results: The majority of patients (81%) had TNM stage III or IV disease. PET-CT was suspicious for pulmonary malignancy in 14 patients (22%) and indeterminate in 6 patients (9%). Pulmonary metastases or a new lung primary were present in 10 patients (16%): 7 of 14 patients with positive PET-CT scans (50%) and 3 of 50 patients with negative or indeterminate PET-CT scans (6%). Including nonpulmonary sites, the overall incidence of distant disease was 23% (15/64) with 20% (13/64) unsuspected prior to PET-CT. The sensitivity and specificity of PET-CT in predicting distant malignancy was 86% and 84%, respectively, with a positive predictive value of 60% and a negative predictive value of 95%. There was a significant correlation between standardized uptake value (SUV) on PET-CT and positive histology, with a mean SUV of 8.5 (range, 4.7-16.2) in patients with distant metastases compared with a mean SUV of 2.9 (range, 1.9-4.2) in patients with benign pathology (r=0.87, P<.0001).